The most interesting thing about this announcement (I predicted it BEFORE the Vista giveaway announcement which I foolishly assumed meant Expression wouldn't be ready in time) is that it implies that Studio will be RTM very soon.

As for the original questions - who cares whether the numbers count towards sales or if they're really free or have been included in the cost (experience of previous giveaways like this would indicate they're buried somewhere in somebody's "marketing" budget rather than "hidden" as part of the conference fee)?

It's a generous offer and one participants should be thankful for. It'll be interesting to see how many of those copies actually get used for anything other than a quick "demo". Like any quality tool they require a great deal of time and investment to learn - that's the REAL cost, and I'm not convinced there's enough for the typical designer to entice him away from what he already knows.